This was a service for providing city-sized chunks of OpenStreetMap data in a variety of geographic data file formats. It's no longer operating.
- Interline OSM Extracts provides extracts for these 200 metro regions (and a few more that have been added since) in PBF, GeoJSON and GeoJSON Lines format. Free. Updated daily.
- Nextzen Metro Extracts provides extracts for these 200 metro regions in the exact same formats as Mapzen Metro Extracts. Free. Updated once (in May 2018).
- Learn OSM provides a guide to other ways of getting OpenStreetMap data.